The present invention relates to a new and improved cushion assembly for cushioning movement of a member in a press during operation of the press and to a method by which the cushion assembly is assembled.
Cushion assemblies have previously been utilized to cushion movement of one or more members in a press. These cushion assemblies commonly include a cylinder in which a piston is movable against the influence of fluid pressure to cushion movement of a member in the press as the press is operated from an open condition to a closed condition. Known cushion assemblies are disclosed in U.S. Pat. Nos. 4,691,902; 6,022,004; and 6,322,059.
Although these known cushion assemblies are generally satisfactory in their construction and mode of operation, there is a continuing effort to simplify the construction of the cushion assemblies in order to increase durability and reliability of the cushion assemblies. In addition, simplifying the construction of the cushion assemblies decreases the cost of the cushion assemblies. When the construction of a cushion assembly is simplified, the number of components which must be maintained by a manufacturer of the cushion assembly may be reduced with a resulting savings in cost.
The present invention includes a new and improved cushion assembly for use in a press. The cushion assembly has tubular cylindrical inner and outer walls. The outer wall encloses lower and upper end walls. The inner wall has lower and upper end portions which are disposed in recesses in the lower and upper end walls. A piston is disposed in the inner wall. A piston rod extends through an opening in the upper end wall.
A passage is formed between an end portion of the inner wall and the lower end wall. This passage conducts a flow of lubrication liquid and gas to lubricate components of the cushion assembly during operation of the press.
The cushion assembly may be assembled by positioning a first lock ring in a first groove formed in an outer wall of the cushion assembly. A first end wall is then moved along an inner side surface of the outer wall into engagement with the first lock ring. A tubular inner wall is positioned in a recess in a second end wall. A piston is positioned in the inner wall. The inner wall, second end wall, and piston are moved together into the outer wall. A second lock ring is then positioned in a second groove formed in the outer wall.